Slurry seal distributing box



June 2, 1970 J. J. MURTAUGH 3,515,041

SLURRY SEAL DISTRIBUTING BOX Filed Feb. 5, 1969 United States Patent O3,515,041 SLURRY SEAL DISTRIBUTING BOX John J. Murtaugh, Waukegan, Ill.,assignor to Rex Chainbelt Inc., Milwaukee, Wis., a corporation ofWisconsin Filed Feb. 5, 1969, Ser. No. 796,856 Int. Cl. E01c 19/48 US.C]. 94-44 12 Claims ABSTRACT OF THE DISCLOSURE A slurry sealdistributing box particularly adaptable for use with slurries comprisinga cationic asphalt emulsion. A rectangular box frame supports agenerally semicircular intermediate retainer which, with the rear frameBACKGROUND OF THE INVENTION Field of the invention 7 The presentinvention pertains to the art of sealing the deteriorated surfaces ofpaved roads with a slurry comprising an emulsified asphalt, fine-grainedaggregate and,

optionally, portland cement. More particularly, the present invention isdirected to a slurry seal distributing box which is towed by a supplyvehicle and is adapted particularly to sealing a paved surface bydepositing thereon a thin layer of slurry containing a cationic asphaltemulsion.

Description of the prior art It is known in the art to seal a pavedsurface by towing a slurry-filled distributing box over the surface andallowing a thin layer of slurry to be extruded from under a laterallyextending, surface engaging squeegee mounted 'on the rear of the box.Prior art boxes have been of generally simple construction consisting ofa rectangular main frame having a lateral dimension corresponding to thewidth of the strip of slurry to be deposited. The longitudinal sideframe members are substantially shorter and have surface-engagingrunners which support the box for sliding movement behind the towingvehicle which also generally serves as the slurry supply vehicle.

The lower edges of the box frame members are provided with resilientsurface-engaging sealing members to maintain the slurry Within the box,the rear sealing member functioning as the squeegee under which theslurry is forced as the box is moved forwardly. Prior art boxes mayadditionally have an intermediate screed or retainer extending laterallyacross the center of the box between the longitudinal side framemembers. The intermediate screed aids in controlling and equalizing theflow of slurry within the box from a central supply point at the frontof the box uniformly across the width of the box to the rear squeegee.

3,515,041 Patented June 2, 1970 Prior art slurry boxes have servedadequately for sealing surfaces with slurries containing an anionic ornegatively charged asphalt emulsion. In recent years, however, anionicasphalt emulsions have been replaced in slurry seals by cationic orpositively charged asphalt emulsions. This change has been made becausecationic emulsions have been discovered to exhibit more desirablechemical properties in slurry seals. A cationic emulsion can be mixedwith a much wider range of types of aggregates to form a slurry thatwill break or set very rapidly upon deposition on a surface to besealed.

Although the rapid break of a cationic slurry is a very desirableproperty, it has been found that use of such slurries in distributingboxes of the prior art causes extensive and extremely undesirablebuild-ups of hardened slurry. The build-up tends to occur primarily inthe corners of the box where the flow of the slurry is retarded andsluggish. Prior art slurry boxes having an intermediate screed have asmany eight corners in which a cationic slurry will break and build upbecause of diminished flow. Not only is the hardened slurry difiicult toclean from the slurry box, but, particularly in the rear corners, abuildup of hardened slurry will interfere with the smooth operation ofthe rear squeegee and cause unevenness and streaking in the layer ofslurry deposited.

SUMMARY OF THE INVENTION The slurry distributing box disclosed hereinprovides an optimum means of spreading a slurry seal comprising acationic asphalt emulsion. The invention resides in the novelconfiguration of the intermediate retainer which forms the forward andlateral walls of the slurry reservoir of the box.

The arcuate shape of the retainer provides a reservoir with a laterallydiminishing cross section so that the slurry supplied to the boxcentrally thereof flows laterally in both directions with an increasingvelocity. As a result, there is a more rapid and positive flow of slurryinto the corners formed by the ends of the retainer and the rear crossmember; and the turbulence created by the rapid flow precludes prematurebreaking or setting of the cationic slurry.

The arcuate configuration of the intermediate retainer eliminates thetwo forward corners of the slurry reservoir of conventional boxes, andthe improved slurry flow characteristics obviate the need for anintermediate screed.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view of aslurry mixing and supply vehicle with a slurry distributing box of thepresent invention operatively attached to the rear thereof.

FIG. 2 is a perspective view of the slurry distributing box of thepresent invention viewed generally from a forward corner thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a slurry seal mixer 1of a known type is mounted on the rear of a standard truck 2. The mixer1 may include storage hoppers and tanks for the various slurryingredients and means for providing continuous batching and supply ofthe slurry. The slurry seal mixture is received from the mixer andspread onto the surface to be sealed by a slurry distributing box 10 ofthe 3 type disclosed herein. The, nected to and towed behind the truckand attached mixer.

Referring to FIG. 2 the slurry distributing box has a generallyrectangular main frame comprising a forward cross frame member 11, arear cross frame member 12, and a pair of side frame members 13. Therearward ends of the side frame members 13 are demountably connected tothe respective ends of the rear cross frame member 12 as with anglebrackets 14 and threaded fasteners 15. The forward ends of the sideframe members are similarly demountably connected to the ends of theforward cross frame member 11. The fastening means used to. interconnectthe main frame members may vary, the primary consideration being toprovide means for rapidly disassembling the members for cleaning thefastsetting cationic slurry.

The lower edges of the side frame members 13 are provided with runners16 adapted to support the slurry box 10 for sliding movement behind atowing vehicle and over the surface to be treated. To provide towingconnection to the towing and slurry supply vehicle, a pair of draw chainclips 17 are attached to the face of the forward cross frame member 11.Each clip 17 is adapted to receive the end of one of a pair of drawchains 17a which chains are attached by their opposite ends to the rearof the vehicle.

The rear cross frame member 12 is disposed with its lower edge 18 abovethe plane of the runners 16 or spaced from the surface to be treated.Attached to and extending downwardly from the lower edge 18 of rearcross frame member 12 is a rear squeegee 19. The squeegee 19 comprises acontinuous strip of relatively thick rubber or other suitable flexibleresilient material and is adapted to engage, along the entire length ofits lower edge, the surface to be treated. The squeegee 19 is bent orflexed in the rearward direction by the forward movement of the slurrybox 10. The slurry within the box is thereby extruded or squeezed underthe squeegee 19 onto the surface in a thin layer.

Since the thickness of the layer of slurry deposited is dependentprimarily upon the maximum size of the aggregate used in the slurry, thesqueegee 19 is, preferably fixed so that its lower edge just engages thesurface to be sealed. The thickness of the layer may, however, be variedslightly by a vertical adjustment, up or down, of the squeegee 19.Several means for providing this adjustment are known and used in theart. One means includes a jack-screw apparatus, such as at 34, adaptedto raise or lower the rear cross frame member 12 relative to the runners16, and another means includes a series of spring-biased adjustingscrews by which the squeegee 19 is attached to the rear cross framemember. Either of these adjusting means may be used with a slurry box ofthe present invention, but neither of them are necessary, and they formno part of the invention.

The intermediate retainer 20 of the present invention is disposed withinthe rectangular main frame of the box and forms with the rear crossframe member 12 and attached squeegee 19 the slurry reservoir. Theretainer 20 is formed of a heavy strip of rubber or other similarmaterial as is the squeegee 19. The retainer preferably has a widthapproximately equal to the height of the slurry box 10 and a lengthsufficient to provide the preferred arcuate configuration in itsoperative position within the box 10, as will be described in. moredetail below. The retainer 20 may be and, depending on whether the boxis adapted for variable width adjustment, preferably is comprised of twooverlapping sections of substantially equal lengths.

The intermediate retainer 20 is secured in position within the box 10 bya series of clamps such that the retainer is vertically disposed withits lower edge coplanar with the runners 16 and the lower edge of thesqueegee 19; i.e., in contact with the surface to be treated. The endsof the retainer are secured to the rearward ends of distributing box 10is conthe side frame members 13 by a pair of side frame clamps 21. Theclamps 21 are demountably attached to the upper edges of the side framemembers 13 and extend downwardly therefrom so that the ends of theretainer 20 are clamped against the inside faces 22 of the side framemembers 13. From its ends the retainer 20 extends in an arcuate mannerforwardly and inwardly within the rectangular main frame such that it issymmetrically disposed with respect to the longitudinal centerline ofthe frame. The midpoint of the retainer lies closely adjacent and intangential relationto the forward cross frame member 11.

The retainer is secured to the forward cross frame member 11 by a pairof cross frame clamps 23 similar to the side frame clamps 21. The crossframe clamps 23 are demountably attached to a pair of triangular-shapedbrackets 24 which are in turn secured to the forward cross frame member11'on opposite sidesof its midpoint. The brackets 24 have downwardlydepending vertical faces against which the retainer 20 is clamped by thecross frame clamps 23, said vertical faces being disposed to maintainthe arcuate shape of the retainer.

A pair of intermediate braces 25 interconnect the forward and rear crossframe members 11 and 12, respectively, to provide added structuralrigidity to the slurry box. Attached to and depending downwardly fromeach brace 25 is a back-up pad 26 disposed intermediate each pair ofclamps 21 and 23. The back-up pads 26 provide additional support to theretainer 20 and aid in main- 'taining the arcuate shape thereof. Theretainer 20 may,

optionally, be secured to the back-up pads with demountable clamps 26a.The vertical surfaces of the pads 26 may be curved to conform moreclosely to the curvature of the retainer, a shown. However, sincecontinuous curvature of the retainer over its entire length is notessential, the vertically disposed surfaces of the pads 26 may be flat.Thus, the retainer, though having a generally arcuate shape in itsmounted position, may have portions which are flattened. In addition tothe portions of the retainer which may be flattened by their abutmentagainst the backup pads 26, the portions by which the retainer ismounted with the clamps 21 and 23 may also be flat.

In operation, the pre-mixed slurry is poured or chuted directly into thereservoir formed by the intermediate retainer 20 and the rear crossframe member '12 and depending squeegee 19. The typical slurry seal mixcomprises an emulsified asphalt and a fine-grained aggregate. A smallpercentage of portland cement may also beincluded.'The slurry is quitefluid in its mixed state and will remain so for a reasonable length oftime if mixing or agitation of the mixed slurry is continued. As isparticularly the case with a slurry containinga cationic asphaltemulsion, a rapid and irreversible break or set will occur on depositionof the slurry on the surface that is being treated. The arcuate shape ofthe intermediate retainer 20 provides a continuing mixing and agitationadapted to prevent breaking of the slurry within the reservoir.

The slurry is generally poured into the box centrally thereof and at apoint just inside the forward cross frame member 11, as by means of achute 36 extending rearwardlyffrom the back of the towing and supplyvehicle. The flow of slurry into the reservoir is adjusted to correspondto the volume of slurry deposited on the surface with the forwardmovement of the box. In this manner the depth of slurry in the reservoiris maintained fairly constannAs the box is moved forwardly, the slurryflows generally radially toward-the rear cross frame member 12 andattached squeegee 19. As can be seen from the drawing, the shape of theretainer 20 conforms very nearly to the natural path of flow'of theslurry from the supply point to the rear corners.

The arcuate retainer 20 eliminates, as a portion of the slurryreservoir, the areas within the main frame adjacent and including theforward corners; i.e. the corners formed by the abutment of the forwardcross frame member 11 and the side frame members 13. Since these areasare outside the natural direct flow path of the slurry, elimination ofthem'eliminates areas where, in prior art boxes, the flow of slurry issluggish and the tendency of the slurry to break and build up isgreatest.

The arcuate shape of the retainer 20 is also adapted to prevent anundesirable build-up of slurry in the rear corners of the box 10. Thelongitudinal cross section of the slurry reservoir is of a laterallydiminishing area and, as a result, the velocity of flow of the slurryfrom the central supply point increases laterally in accordance with theprinciples of fluid flow. The flow velocity is a maximum at or near therear corners and is of a magnitude, within the range of forwardoperating speed of the box, suflicient to create a turbulence in theslurry which prevents a premature break and consequent build-up,particularly in the corners.

To allow selective adjustment of the width of the box, the forward andrear cross frame members 11 and 12, respectively, are provided withtelescoping extensions. Thus, the forward cross frame member 11 includesa pair of forward cross frame extensions 27 adapted to interfittelescopingly within the ends of the central section 28 of the member11. The extensions 27 may be slidably positioned to the desired widthand secured in position, as by bolts 29 extending through a series ofmatching holes in the interfitting portions of the central section 28and the extensions 27. Similarly, the rear cross frame member 12includes a pair of rear cross frame extensions 30 adapted to be slidablypositioned within the ends of the intermediate section 31 of the member12 and secured in position in a suitable manner, such as with bolts 32.

Because of the arcuate shape and flexibility of the intermediateretainer 20', the width of the box may be varied within limits and aspreviously described merely by additionally adjusting the back-up pads26. Preferably, however, the box should be adjustable over a greaterrange of Widths than is possible with a single-piece retainer 20. Thus,the retainer comprises two substantially identical overlapping portions33 of sufficient lengths so that the width of the retainer 20 may beadjusted to correspond to the selected width of the box withoutsubstantially changing the general arcuate shape of the retainer.

The improved slurry flow characteristics produced by the retainer 20obviate the need for an intermediate screed. The elimination of anintermediate screed eliminates the forward portion of the two-partreservoir common in prior art boxes and, thus, four additional cornerswhere slurry may prematurely set and build up.

To provide a more positive seal at the rear corners and to furtherfacilitate cleaning, the box may be provided with corner seals 35. Theseseals 35 are made of relatively short pieces of a material similar tothat comprising the intermediate retainer 20 and rear squeegee 19. Thecorner seals 35 are secured at one of their respective ends to the sideframe members 13, along with the ends of the retainer 20, by clamps 21such that the lower edges of the seals engage the surface upon which thebox is resting. The seals are bent around the rear corners such thattheir opposite free ends lie against the ends of the rear cross framemember 12. The pressure of the slurry in the reservoir, along with theinherent resiliency of the seal material, maintains the free ends of thecorner seals in position. Alternately, the corner seals 35 may compriseintegral extensions of the ends of the retainer 20. In either case, theseals are readily removable with disassembly of the box to furtherfacilitate simple and rapid cleaning.

Although the invention has been shown and described with reference to aparticular embodiment, it will be understood by those skilled in the artthat various changes may be made therein, in form and detail, withoutdeparting from the spirit and scope of the invention.

What is claimed is: j

1. In an apparatus for applying a slurry seal mixture to a surface to besealed including a prime mover operable in a given direction, a slurryreceiving and distributing device comprising: a supporting frame, aflexible resilient retainer arcuately disposed within said frame andattached thereto by its ends and mid-portion such that said retainer isrearwardly Open respecting the direction of operation, said retainerhaving a lower edge in contact with the surface to be sealed, andsealing means including a'surface engaging squeegee operativelyassociated with said retainer to form a slurry retaining reservoir, saidsqueegee being deformable by the forward movement of said device wherebythe slurry within said reservoir is extruded under said squeegee in athin layer onto the surface to be sealed.

2. The invention of claim 1 wherein said supporting frame comprises apair of longitudinally extending surface engaging side frame members anda forward cross, frame member demountably interconnecting the forwardends of said side frame members.

3. The invention of claim 2 wherein said sealing means further includesa rear cross frame member demountably connected by its ends to therearward ends of said side frame members.

4. The invention of claim 2 wherein said retainer is demountablyattached to said supporting frame.

5. The invention of claim 3 wherein said cross frame members and saidretainer are laterally extensible whereby the width of said device maybe selectively varied.

6. A slurry seal distributing box adapted to be moved over a surface tobe sealed, comprising: a pair of longitudinally extending surfaceengaging side frame members, a forward cross frame memberinterconnecting the forward ends of said side frame members, a rearcross frame member interconnecting the rearward ends of said side framemembers, a flexible resilient intermediate retainer arcuately disposedwithin said interconnected frame members and attached by its respectiveends to the rearward ends of said side frame members and by a portionintermediate its ends to said forward cross frame member such that thelower edge of said retainer is substantially coplanar with the surfaceengaging edges of said side frame members, and a squeegee attached toand extending downwardly from the lower edge of said rear cross framemember such that the lower edge of said squeegee is substantiallycoplanar with the lower edge of said retainer and forms therewith asurface engaging static seal to retain the slurry therein, said squeegeebeing deformable by the forward movement of said box such that theslurry is extruded under said squeegee in a uniformly thin layer overits entire length.

7. The invention of claim 6 wherein said forward and rear cross framemembers each comprise at least one pair of interfitting telescopingmembers laterally adjustable to selectively vary the width of said boxand thereby vary the width of the layer of slurry deposited.

8. The invention of claim 6 wherein the ground engaging edges of saidside frame members comprise a pair of runners adapted to support saidboxfor sliding movement behind a towing vehicle.

9. The invention of claim 7 wherein said frame members are demountablyinterconnected and said retainer is demountably attached to said forwardcross frame member and said side frame members.

10. The invention of claim 7 wherein said intermediate retainercomprises at least two overlapping portions whereby its length may beselectively varied to correspond to the selected width of said box.

11. The invention of claim 10 wherein said retainer is additionallysupported intermediate its attachment to said forward cross frame memberand its respective attachments to said side frame members by apair ofadjustable baek-up pads, whereby the afeuafe -configuraticn of said'i'etainer, may be inaintained regardless of the selected "width atwhich said box is operated.

' 1 2.-The-inventid 9f 'c1aim 9'inc1 1dinga pair of de- 5 mountable co-ner' seals of a flexible resilient material each attached by'one of itsends to the'l earward end of one of said side frame members and adaptedto be bent around the'cq rner fo r nedby said side framemember-and saidrear 'crossframe member and to 'rest against the inside 10 surfacethereof.

References "citd' v I UNITED ATES PATENTS;

Sub; 94-46 .IANILE c. BYERS, ii- Primary Examiner

